The present invention refers to a food cooking oven, in particular of the kind intended for use in catering and foodservice applications, provided with special features adapted to inform the operator, ie. the user about the bacterial count persisting in the food being handled, and in particular to give an information about the period of time during which the just cooked food can be kept stored, ie. can be preserved.
Food cooking oven are generally known to operate by transferring heat from the outside of the food being cooked to the inside thereof, and this circumstance unavoidably leads to the fact that the food itself is caused to undergo a differing heat treatment: in particular, the innermost portion of the food is capable of reaching the appropriate cooking temperature within a definitely longer time and, conclusively, this innermost portion generally is cooked to a lesser extent.
This phenomenon, which by the way is largely known in the art, is of particular relevance and significance in connection with those kinds of foodstuffs that come in the form of a compact mass with an outward facing surface that is rather small as compared wit the inner volume of the food; these kind of foodstuffs are mainly represented by whole pieces of meat, rolled meat pieces, pieces of minced meat such as meat loaves and the like.
In view of doing away with such a typical phenomenon of a non-homogeneous cooking effect or a poor cooking effect in the interior of the food being handled, it is a generally known practice in the art to provide some kind of thermometric probes, such as in particular the widely used pin-type core temperature probes, which are introduced in the interior of the food mass being cooked. The temperature information that is delivered by such probes is then used to control the cooking cycle, as an alternative to the cooking cycles that are on the contrary programmed according to the cooking time.
However, even such a use of core temperature probes is not sufficient in view of solving the problem of delivering a correct information about the risk that a food, although having been cooked, may still retain an unacceptably elevated bacterial count.
It is in fact a largely known fact that the residual bacterial content in a cooked food depends to a substantial extent on the actual time during which a given minimum temperature level is allowed to persist in the same food, ie. on the same food being allowed to remain at a minimum temperature level for a definite period of time, and such an information is not automatically and readily available in prior-art cooking ovens. As a matter of fact, in prior-art ovens the temperature is detected either in a continuous manner or at pre-determined intervals during the cooking cycle, and it is only at the end of such a cooking cycle that a skilled operator is able to judge whether the residual bacterial content in the cooked food is at an acceptable level or not.
However, such an information can solely be inferred, ie. is solely available if the operator of the oven is adequately trained to do such kinds of assessments, and even in his case only at the end of the cooking process, so that if the residual bacterial content is judged to be still in excess of an acceptable level, owing to the cooking cycle being already concluded, potentially dangerous conditions of uncertainty may well arise.
Furthermore, no automatic indication is given or available about the actual length of the period of time during which the just cooked food may be kept in store, ie. preserved before the bacterial content is likely to rise again to an unacceptable level. Last, but not least, if a thermometric core temperature probe inserted in the food to be cooked is used to control the cooking cycle, there is no certainty at all that the thereby measured temperature is actually the temperature prevailing in the coldest point within the food.
For instance, said solution is divulged form WO 01/73352, illustrating an invention that concerns a cooking device comprising a chamber for food provided with heating means with controlled operation, and room and internal temperature sensors, means for acquiring internal and room temperatures and a minimal decontamination value and a control module for monitoring the heating means in accordance with parameters based on the internal and room temperatures input and the decontamination value input; however said solution presents the above cited drawback that the measured temperature is actually the temperature prevailing in the coldest point in the food, and furthermore the control of the heating means based also on the cooking chamber temperature cannot assure that the temperature inside the food will rise at a pre-defined level for a given lenght of time.
From EP 0 794 387 a method for estimating the temperature of the inner portion of material to be cooked and thermal cooking apparatus using the same method are divulged; however said document does not teach how to solve the problems due to the detection of the actual lower temperature inside the food, and moreover the proposed method appears complicate and something unreliable due to the need that the physical properties of the food have to be learned and entered in the relevant oven.
A further basic element of uncertainty and, therefore, of potential dangerousness is due to the fact that the various foodstuffs have widely differing properties, ie. behave in a totally different manner in this connection, so that, as all those skilled in the art are well aware of, the bacterial count of a certain food that has gone through a standard cooking cycle, and that for this reason may then feature a significantly reduced bacterial content, can on the contrary turn out to be still unacceptably elevated in another kind of food that is treated using the same cooking cycle.
Finally, a further element that is placing pressure on the manufacturers of foodservice equipment in general, including food cooking ovens, is the European Directive no. 93/43 (the so-called HACCP-Directive, where the acronym stands for Hazardous Analysis and Critical Control Point), which is aimed at introducing hygiene, health-safeguard and safety requirements in food processing, cooking and storage equipment and processes.
The need is therefore strongly felt for providing a food cooking oven, particularly intended for foodservice and catering applications, which allows for the above mentioned drawbacks and risk situations to be right away eliminated or at least reduced to acceptable levels, and whose construction is not only simple, but makes also use of readily available techniques. Furthermore, the utilization of such a kind of oven shall be simple and filly within the capability of a normally skilled operator of food cooking ovens, in particular food cooking ovens used in foodservice and catering applications.
These aims, along with further features of the present invention are reached in a food cooking oven that is made and operates in accordance with the characteristics that are recited in the appended claims.